Luteal P4 synthesis in early pregnant gilts after induction of estrus with PMSG/hCG.

The present study was designed to examine whether an estrus induction with gonadotropins could affect luteal P4 synthesis in early pregnant gilts. Sixteen prepubertal gilts received 750IU of PMSG and 500IU of hCG 72h later. Prepubertal gilts in the control group (n=17) were observed daily for estrus behavior.

Prostacyclin receptor (PTGIR) in the porcine endometrium: Regulation of expression and role in luminal epithelial and stromal cells.

The prostacyclin (PGI2) signaling pathway plays an important role during early pregnancy in rodents and ruminants. Abundant concentrations of PGI2 were also found in the endometrium and uterine lumen of gilts during the period of implantation. The present study was designed to examine (1) the expression of PGI2 receptor (PTGIR) messenger RNA (mRNA) and protein in the endometrium of cyclic and early-pregnant gilts; (2) possible regulation of endometrial PTGIR gene expression by conceptus products, estradiol and cytokines; (3) the effect of iloprost (a PGI2 analogue) on cAMP formation and the expression of fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF; isoform 164) mRNA in luminal epithelial (LE) and stromal (ST) cells.

Effect of oestrus synchronization with PGF2α/eCG/hCG on luteal P4 synthesis in early pregnant gilts.

Administration of hormones to synchronize oestrus is a useful tool in animal breeding. However, exogenous ovarian stimulation may be detrimental to reproductive function. This study was aimed to examine whether an oestrus synchronization with PGF2α/eCG/hCG could affect luteal P4 synthesis in early pregnant gilts.

Expression profile and role of prostacyclin receptor (PTGIR) in peri-implantation porcine conceptuses.

Prostacyclin (prostaglandin I2 [PGI2]) signaling system not only plays a pivotal role in vascular function in many species but is also important during early pregnancy in rodents and ruminants. Recently, abundant concentrations of PGI2 were found in the endometrium and uterine lumen of gilts at the time of implantation. In the present study, conceptuses collected on Days 10, 12, 14, 16, and 18 of pregnancy were examined for the expression of PGI2 receptors, PTGIR.

Effect of conceptus on transforming growth factor (TGF) β1 mRNA expression and protein concentration in the porcine endometrium--in vivo and in vitro studies.

Transforming growth factor (TGF) β and its receptors are expressed at the conceptus-maternal interface during early pregnancy in the pig. The present studies were conducted to examine: (1) the effect of conceptus products on TGFβ1 mRNA expression and protein concentration in the porcine endometrium using in vivo and in vitro models, and (2) the effect of TGFβ1 on proliferation of porcine trophoblast cells in vitro. During in vivo experiments, gilts with one surgically detached uterine horn were slaughtered on days 11 or 14 of the estrous cycle and pregnancy.